ZIAA ARCHIVE RECORDANOMALY POST-MORTEMS
INC-2022-05failureVERIFIED RECORD
HORN-CANCEL: Phase Cancellation Anomaly in Concentric Waveguide Horn
INC-2022-05HAZARD: ACOUSTIC_PHASE_NULLSTATUS: DEFECTIVE_HORN_RECYCLED_REBUILTINCIDENT DATE:
HORN-CANCEL: Phase Cancellation Anomaly in Concentric Waveguide Horn
Lead Investigator: Soren Lindqvist
INCIDENT NARRATIVE
A prototype concentric exponential horn speaker (PROT-015) fabricated from spun aluminum exhibited a severe, unexpected 38 dB notch filter across the core human vocal band during anechoic chamber measurements. Listening subjects reported extreme perceptual isolation and hollow speech intelligibility.
ROOT CAUSE ANALYSIS
CNC lathe path calculation error introduced a 2.4mm step in the internal throat expansion profile, creating a standing wave anti-node that canceled mid-range frequencies.
CONTAINMENT PROTOCOL
3D acoustic simulation in COMSOL now precedes all physical horn machining. Throat profile re-turned to true continuous exponential curvature.
SALVAGED / REASSIGNED HARDWARE
Compression Driver UnitCast Iron Mounting FlangeCrossover Network